tree 792a29815f32475480dd9740f1cb572851cf421d
parent 48ba745eacf883080152fe16b5b1305657d001ca
author Richard Smith <richard@metafoo.co.uk> 1585963337 -0700
committer Richard Smith <richard@metafoo.co.uk> 1585963574 -0700

PR45402: Make the restrictions on constant evaluation of memcmp and
memchr consistent and comprehensible, and document them.

We previously allowed evaluation of memcmp on arrays of integers of any
size, so long as the call evaluated to 0, and allowed evaluation of
memchr on any array of integral type of size 1 (including enums). The
purpose of constant-evaluating these builtins is only to support
constexpr std::char_traits, so we now consistently allow them on arrays
of (possibly signed or unsigned) char only.